Container apparatus and related methods

ABSTRACT

A container includes: a base; one or more sidewalls integrally formed with and extending upwardly from the base, wherein the sidewalls surround an internal cavity and wherein one or more of the sidewalls include a reinforcing web of increased wall thickness; and an upper edge on the sidewalls defining a top opening.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/222,912, filed Aug. 19, 2008, entitled “CONTAINER APPARATUS ANDRELATED METHODS” which is a continuation of PCT/US2007/087321, filedDec. 12, 2007 entitled “CONTAINER APPARATUS AND RELATED METHODS.”

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to containers and methods ofmanufacturing containers.

2. Discussion of the Related Art

Containers are useful and necessary in human society. In modern commerceand applications, they are used in a vast array of applications, somemore demanding than others.

To be economically and environmentally efficient, containers (like othermanufactured items) need to use a minimum amount of material. Not onlydoes this reduce the waste that results at the end of the container'suseful life, it also reduces the costs of materials to manufacture thecontainer, reduces the transportation costs that can be involved inusing the container, and provides other benefits. For containers madefrom plastic or similar materials, the rising costs of materials and theneed for ecological responsibility can be substantial.

On the other hand, many or even most containers require some degree ofreliable structural integrity. Among other things, they may be stackedthree or four (or more) high on pallets for storage and/ortransportation, and possibly have other pallets or objects stacked ontop of those stacks.

Square, rectangular, or other cornered containers can more efficientlyuse a given volume of space on a pallet and/or in a warehouse or retailstore (as compared to conventional round plastic buckets). They canbenefit from the foregoing reduction in material usage, and can provideinteresting design and performance challenges as compared tonon-cornered containers.

Design and performance characteristics for a container or other productalso may be important with respect to material selection. For example,in certain applications, one material may be preferred or even requiredinstead of another (e.g., polypropylene instead of polyethylene) inorder to meet the performance criteria (such as withstanding anticipatedvertical compression loads or other forces).

In addition, reducing the non-material costs of manufacture alsoimproves the economics and ecological considerations of making and usinga given container. For example, to the extent that the energyrequirements for making a given container can be reduced, the economicand environmental characteristics of the container and fabricationprocess are also improved. For applications and processes such asinjection molding of plastic containers or other products, a lowerinjection pressure (to inject the plastic into a mold) can mean thatless energy is needed to manufacture that product.

Accordingly, it is desirable to provide methods and apparatus forcontainers having sufficient strength and durability to withstand heavyloads and predictable storage and handling risks, while reducing costsand usage of materials and providing other benefits.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to containers and methodsof manufacturing the same that substantially obviate one or more of theproblems due to limitations and disadvantages of the related art.

An advantage of the present invention is to provide containers andmethods of manufacturing containers having improved strength-to-materialand/or strength-to-weight ratios.

Another advantage of the present invention is to provide containers andmethods of manufacturing containers that reduce the raw materialsrequired for manufacturing the containers.

Another advantage of the present invention is to provide containers andmethods of manufacturing containers that reduce the energy required formanufacturing the containers.

Another advantage of the present invention is to provide containers andmethods of manufacturing containers that reduce the waste that resultsat the end of the container's useful life.

Another advantage of the present invention is to provide containers andmethods of manufacturing containers that reduce the transportation costsassociated with using the containers.

Another advantage of the present invention is to provide containers andmethods of manufacturing containers that more efficiently use a givenvolume of space.

Additional features and advantages of the invention will be set forth inthe description which follows, and in part will be apparent from thedescription, or may be learned by practice of the invention. Theobjectives and other advantages of the invention will be realized andattained by the structure particularly pointed out in the writtendescription and claims hereof as well as the appended drawings.

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described, a containerincludes: a substantially solid base and at least three sidewallsintegrally formed with and extending upwardly from the base and havingcorners portions therebetween, an internal cavity formed by thesidewalls and the corner portions, the internal cavity having with anopening opposite the base; wherein the sidewalls and corner portionsinclude a continuous integral reinforcing web extending from thesidewalls and corner portions into the internal cavity; wherein thecorner portions have a curved cross-section of predetermined radius ofcurvature wherein the predetermined radius of curvature is substantiallyconstant through the height of the corner portions; and wherein theintegral reinforcing web has a repeating geometric pattern having apattern frequency, wherein the pattern frequency is the substantiallythe same in the corner portions and the sidewalls.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention.

In the drawings:

FIG. 1 is a lower perspective view of a container according to a firstembodiment of the present invention.

FIG. 2 is an elevated perspective view of the container of the firstembodiment of the present invention.

FIG. 3 is a sectional view of the upper surface of the bottom of thecontainer, sectioned along plane A-A of FIG. 2.

FIG. 4 is sectional view of the upper surface of the bottom of thecontainer section along plane B-B of FIG. 2.

FIG. 5 is an enlarged partial view taken along line C-C of FIG. 4.

FIG. 6 is an enlarged partial view taken along line D-D of FIG. 5.

FIG. 7 is an enlarged partial view taken along line E-E of FIG. 3.

FIG. 8 is an elevational sectional view taken along line F-F of FIG. 2.

FIG. 9 is an elevational sectional view taken along line G-G of FIG. 2.

FIG. 10 is an enlarged partial view taken along line H-H of FIG. 9.

FIG. 11 is an isometric sectional view taken along line F-F of FIG. 2.

FIG. 12 is an isometric sectional view taken along line G-G of FIG. 2.

FIG. 13 is an enlarged partial view taken along line I-I of FIG. 11.

FIG. 14 is an enlarged partial view taken along line J-J of FIG. 13.

FIG. 15 is an upper perspective view of a container according to asecond embodiment of the present invention.

FIG. 16 is a upper perspective sectional view of the container of FIG.15.

FIG. 17 is an enlarged partial view taken along line K-K of FIG. 16.

FIG. 18 is an isometric view of a container according to a thirdembodiment of the present invention.

FIG. 19 is a section view of the container of FIG. 18.

FIG. 20 is an isometric view of a container according to a fourthembodiment of the present invention.

FIG. 21 is sectional view of the container and lid of FIG. 20.

FIG. 22 is an isometric bottom view of the lid of FIG. 20.

FIG. 23 illustrates corner cross-sections according to certainembodiments of the present invention.

FIG. 24 is an substantially diamond-shaped web pattern according tocertain embodiments of the present invention.

FIG. 25 is a circular web pattern according to certain embodiments ofthe present invention.

FIG. 26 is a combination of diamonds and vertical bars as a web patternaccording to certain embodiments of the present invention.

FIG. 27 is a triangular web pattern according to certain embodiments ofthe present invention.

FIG. 28 is a rectangular web pattern according to certain embodiments ofthe present invention.

FIG. 29 is an elevation view of a web pattern formed in a sidewallaccording to certain embodiments of the present invention.

FIG. 30 is an elevation views of a web pattern formed in a sidewallaccording to certain embodiments of the present invention.

FIG. 31 is an elevation views of another web pattern formed in asidewall according to certain embodiments of the present invention.

FIG. 32 is an elevation views of still another web pattern formed in asidewall according to certain embodiments of the present invention.

FIG. 32 is an elevation views of still another web pattern formed in asidewall according to certain embodiments of the present invention.

FIG. 33 is a cross-section of the corners of two nested containers ofhaving a generally constant (non-tapering) radius of curvature in theirrespective corner sections.

FIG. 34 is a cross-section of the corners of two nested containershaving a generally tapered radius of curvature.

FIG. 35A is a side view of two nested containers having a substantiallyconstant corner radius.

FIG. 35B is a section view of taken along line 35B-35B of FIG. 35A.

FIG. 36A is a side view of two nested containers having a tapered cornerradius.

FIG. 36B is a section view of taken along line 36B-36B of FIG. 36A.

FIG. 37A is a side view of two nested containers having a substantiallyconstant corner radius with reinforcing web diamond patterns.

FIG. 37B is a section view of taken along line 37B-37B of FIG. 37A.

FIG. 38A is a side view of two nested containers having a substantiallytapered radius with reinforcing web diamond patterns.

FIG. 38B is a section view of taken along line 38B-38B of FIG. 38A.

FIG. 39 is a overhead view of according to another embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Reference will now be made in detail to embodiments of the presentinvention, examples of which are illustrated in the accompanyingdrawings.

FIGS. 1-14 illustrate a container according to a first embodiment of thepresent invention. The following description describes the firstembodiment with reference to these figures.

As illustrated in FIG. 1, container 10 includes a base 16, sidewalls 12extending upwardly from the base, and an upper edge 40 on the sidewalls12 defining a top opening. The sidewalls 12 surround an internal cavityand, together with the base 16 and upper edge 40, define the internalcavity. Container 10 further includes a gate site 17 located at thecenter of the base 16, corners 20 located between adjacent sidewalls 12,horizontal ribs 50 extending around the upper portion of the sidewalls12, handles 52 and attachment points 54 integrally formed with thehorizontal ribs 50, and an engaging lip on the upper edge 40 configuredto matingly engage with a corresponding lid. The base 16, sidewalls 12,upper edge 40, gate site 17, corners 20, horizontal ribs 50, handles 52and attachment points 54 are all integrally formed with each other. Inthis embodiment, container has a substantially rectangular footprint.

As illustrated in FIG. 2, sidewalls 12 and corners 20 of the container10 include a reinforcing web 30 on their inside surfaces, extendingsubstantially the full height of the sidewalls 12 and corners 20 andterminating near the top and bottom of the sidewalls 12. The reinforcingweb 30 includes channels having an increased wall thickness as comparedto adjacent non-web portions. The channels are patterned into a seriesof rows and columns, specifically an upright diamond pattern when viewedin elevation. The reinforcing web 30 on the corners 20 is substantiallya continuation of the upright diamond pattern present on the otherportions of the sidewalls 12. As shown, the reinforcing web 30 patternis substantially centered along the vertical centerline of the corners20. Additionally, FIG. 2 illustrates vertical ribs 60 at the lowerportion of the corners 20 near the base 16. The vertical ribs 60 andreinforcing web 30 are integrally formed with each other and with thecorners 20 and sidewalls 12.

As illustrated in FIG. 3, the base 16 of the container 10 includes thegate site 17 and includes flow leaders 18 on the upper surface of thebase 16. The flow leaders 18 connect to and extend outwardly from thegate site. The flow leaders 18 have increased thickness relative to thewall thickness of the base. As shown, the flow leaders 18 aresubstantially uniformly distributed around the gate site 17. In FIGS. 3and 4, the flow leaders 18 connect to the channels of the reinforcingweb 30. Furthermore, a comparison of FIGS. 3 and 4 shows that thecurvature of the corners 20 is substantially constant throughout theheight of the container.

As illustrated in FIG. 5, the wall thickness of the corners 20 isthicker than the rest of the sidewall 12. In FIG. 6, the channels of thereinforcing web 30 have a thickness greater than the thickness of thesurrounding sidewall 12 and corner 20. For example, the wall thicknessof the sidewall 12/corner 20 at the reinforcing web 30 (at locations aand c) are greater than the adjacent non-web portions (such as locationsb and d). Also, FIG. 6 further illustrates that the channels of thereinforcing web 30 have a tapered shape, gradually tapering to a maximumthickness near the center of the channel's cross-section. In the firstembodiment, the channels of the reinforcing web 30 have curved exteriorsurfaces. FIG. 7 illustrates an enlarged portion of the base 16including flow leaders 18.

FIGS. 8 and 9 are sectional views taken from the sides of the container10 illustrating how the intersection of two curved exterior surfaces(which can be viewed as intersecting crescents or half-moons) results invarious horizontal and/or vertical lines occurring at the intersections.The lines are simply the visible exterior surface result of two curvedgeometries intersecting each other. FIG. 10 illustrates that the flowleaders 18 have a thickness greater than the thickness of thesurrounding base 16.

FIGS. 11 and 12 are additional sectional views taken from the sides ofthe container 10 illustrating that each lowermost channel of thereinforcing web 30 connects to a flow leader 18 and each flow leader 18connects to two lowermost channels of the reinforcing web 30. FIGS. 13and 14 illustrate the reinforcing web 30 patterns in greater detail.

FIGS. 15-17 illustrate a container according to a second embodiment ofthe present invention. The following description describes the secondembodiment with reference to these figures.

FIGS. 15-17 illustrate a round bucket-type container 10 including a base16, sidewall 12 extending upwardly from the base 16, and an upper edge40 on the sidewall 12 defining a top opening. The sidewall 12 surroundsan internal cavity and, together with the base 16 and upper edge 40,define the internal cavity. Container 10 further includes handles 52 andhas a substantially round footprint.

The sidewall 12 of the container 10 includes a reinforcing web 30 on itsinside surface, extending substantially the full height of the sidewall12 and terminating near the top and bottom of the sidewall 12. Thereinforcing web includes channels having an increased wall thickness ascompared to adjacent non-web portions. The channels are patterned into aseries of rows and columns distributed generally uniformly about thecircumference of the container, specifically an upright diamond patternwhen viewed in elevation. The channels of the reinforcing web 30 havecurved exterior surfaces. The intersection of two curved exteriorsurfaces results in various horizontal and vertical lines occurring atthe intersections as shown in FIG. 17.

The base 16 of the container 10 includes a gate site 17 and flow leaders18 on the upper surface of the base 16. The flow leaders 18 connect toand extend outwardly from the gate site. The flow leaders 18 haveincreased thickness relative to the wall thickness of the base. The flowleaders 18 are substantially uniformly distributed around the gate site17 in a criss-cross web pattern.

FIGS. 18-19 illustrate a container according to a third embodiment ofthe present invention. The following description describes the thirdembodiment with reference to these figures.

Container 10 includes a base 16, sidewalls 12 extending upwardly fromthe base, and an upper edge 40 on the sidewalls 12 defining a topopening. The sidewalls 12 surround an internal cavity and, together withthe base 16 and upper edge 40, define the internal cavity. Container 10further includes a gate site 17 located at the base 16, corners 20located between adjacent sidewalls 12, horizontal ribs 50 extendingaround the upper portion of the sidewalls 12, handles 52 and attachmentpoints 54 integrally formed with the horizontal ribs 50, and an engaginglip on the upper edge 40 configured to matingly engage with acorresponding lid. The base 16, sidewalls 12, upper edge 40, gate site17, corners 20, horizontal ribs 50, handles 52 and attachment points 54are all integrally formed with each other. The curvature of the corners20 is substantially constant throughout the height of the container. Inthis embodiment, container has a substantially square footprint.

Sidewalls 12 of the container 10 include a reinforcing web 30 on theirinside surfaces, extending substantially the full height of thesidewalls 12 and corners 20 and terminating near the top and bottom ofthe sidewalls 12. The reinforcing web 30 includes channels having anincreased wall thickness as compared to adjacent non-web portions. Thechannels are patterned into a series of rows and columns. Additionally,vertical ribs 60 at the corners 20 extend along substantially the entireheight of the sidewalls 12.

FIGS. 20-22 illustrate a container according to a fourth embodiment ofthe present invention. The following description describes the fourthembodiment with reference to these figures.

Container 10 includes a base 16, sidewalls 12 extending upwardly fromthe base, and an upper edge 40 on the sidewalls 12 defining a topopening. The sidewalls 12 surround an internal cavity and, together withthe base 16 and upper edge 40, define the internal cavity. Container 10further includes a gate site 17 located at the base 16, corners 20located between adjacent sidewalls 12, horizontal ribs 50 extendingaround the upper portion of the sidewalls 12, handles 52 and attachmentpoints 54 integrally formed with the horizontal ribs 50, and an engaginglip on the upper edge 40 configured to matingly engage with acorresponding lid 70. The base 16, sidewalls 12, upper edge 40, gatesite 17, corners 20, horizontal ribs 50, handles 52 and attachmentpoints 54 are all integrally formed with each other. In this embodiment,container has a substantially rectangular footprint.

Sidewalls 12 and corners 20 of the container 10 include a reinforcingweb 30 on their inside surfaces, extending substantially the full heightof the sidewalls 12 and corners 20 and terminating near the top andbottom of the sidewalls 12. The reinforcing web 30 includes channelshaving an increased wall thickness as compared to adjacent non-webportions. The channels are patterned into a series of rows and columns,specifically an upright diamond pattern when viewed in elevation. Thereinforcing web 30 on the corners 20 is substantially a continuation ofthe upright diamond pattern present on the other portions of thesidewalls 12. As shown, the reinforcing web 30 pattern is substantiallycentered along the vertical centerline of the corners 20. Additionally,FIG. 2 illustrates vertical ribs 60 at the lower portion of the corners20 near the base 16. The vertical ribs 60 and reinforcing web 30 areintegrally formed with each other and with the corners 20 and sidewalls12.

The base 16 of the container 10 includes the gate site 17 and includesflow leaders 18 on the upper surface of the base 16. The flow leaders 18connect to and extend outwardly from the gate site 17. The flow leaders18 have increased thickness relative to the wall thickness of the base16. As shown, the flow leaders 18 are substantially uniformlydistributed around the gate site 17. The flow leaders 18 connect to thechannels of the reinforcing web 30. The channels of the reinforcing web30 have curved exterior surfaces. The intersection of two curvedexterior surfaces results in various horizontal and vertical linesoccurring at the intersections as shown in FIG. 21. The lowermostchannel of each reinforcing web 30 connects to a flow leader 18 and eachflow leader 18 connects to two lowermost channels of the reinforcing web30.

According to FIG. 22, the lid 70 includes a reinforcing web 30 on itslower surface, extending substantially across the full lower surface andterminating near the four corners of the lid 70. The reinforcing web 30includes channels having an increased wall thickness as compared toadjacent non-web portions. The channels are patterned into a series ofrows and columns, specifically a diamond pattern.

The following description relates to additional embodiments of thepresent invention.

Containers may include a base, one or more sidewalls extending upwardlyfrom the base, and an upper edge on the sidewalls defining a topopening. The sidewalls surround an internal cavity and, together withthe base and upper edge, define the internal cavity. The sidewalls maybe attached to or integrally formed with the base. The wall thickness ofthe sidewalls and the base may be varied at locations around containersand may include corrugations to provide more or less strength or weight.The upper edge may include an engaging lip configured to matingly engagewith a corresponding lid. Containers may have a substantiallyrectangular, square, round or other-shaped footprint. The general andspecific shape and dimensions of the containers may be configured acrossa wide range, depending on the materials used, the applications forwhich the container is intended, and other factors. In one embodiment,the container has a four gallon capacity.

Containers may have one or more corners located between adjacentsidewalls or may be non-cornered. Square, rectangular and other corneredcontainers more efficiently use a given volume of space compared tonon-cornered containers. Various corner cross-sections may be used,including single-concave, double-concave, angled corners, convex, wavy,centered vertical channel with one or more grooves on each side, or oneor more sharp angles combined to wrap around a corner. FIG. 23illustrates: a curved corner similar to the first, third and fourthembodiments (A); a double-concave corner (B); a single concave corner(C); and an angled corner (D). The angle corner includes four bent lineswith generally straight sections between them to traverse anapproximately 90 degree corner.

Sidewalls may include an integral reinforcing web of increased wallthickness as compared to adjacent non-web portions for providingstructural support to the sidewalls. The reinforcing web strengthens thesidewalls of the container and thereby improves the strength-to-materialand/or strength-to-weight ratios of the entire container. Thereinforcing web improves the container's resistance to collapse due tosidewall buckling and stacking forces (compression loads imposedgenerally vertically downwardly due to stacking) that occur when thecontainer is loaded with product or is in a stack of heavy objects, suchas other containers. Thus, thinner walls can carry greater loads, andweb-reinforced containers obtain performance characteristics achieved bynon-webbed containers using more total material and having more totalweight. Therefore, less raw materials are needed for webbed containersand transportation costs are reduced because the container weighs less.Additionally, web-reinforced containers may help containers absorbenergy impacts (such as from being dropped or otherwise impacted),functioning as a spring to allow slight deformation without failure, andmay even rebound or spring back into the containers original desiredshape.

The reinforcing web may include channels having an increased wallthickness as compared to adjacent or underlying wall thickness. Thechannels may be patterned into a series of rows and columns. Thechannels may have a tapered shape, for example, gradually tapering to amaximum thickness near the center of the channel's cross-section, and/orhaving curved exterior surfaces. Tapered channels improve theperformance of the container. For example, emptying or dispensing thecontainer's contents during use becomes easier and/or more complete,reduced flexibility due to sharp edges that harden the container inthose sharp areas is avoided by spreading stresses/loads throughoutchannel, and the container is released faster from a nested state.Furthermore, when employed in the context of a molding process, themolding process may be improved. For example, the molded container iseasier to remove from the mold, the amount of material required to forma suitable container is decreased and the molten material more easilydispenses through the mold.

Note that curved exterior channel surfaces result in various horizontaland/or vertical lines occurring at the intersections in the figures.Materials flowing into the mold (which eventually forms the container)are not blocked by the intersection lines since the lines are simply thevisible exterior surface results of two curved geometries intersectingeach other. For embodiments where channel surfaces are flat and notcurved, intersection lines do not exist.

The channel shapes of the reinforcing web may be arranged in a specificpattern. The pattern may be any that provide the desired benefits,including circles, ovals, arches, rectangles, hexagons, honeycombs,triangles, other sizes and shapes of diamonds, combination of diamondsand vertical bars. The pattern may include sharp or smooth patterns orelements, a mix of various patterns, mixed sizes of the size ordifferent shapes, spaces irregularities within an otherwise regularpattern, or may even be somewhat random. Selection of reinforcing webpattern design can be especially helpful and important in improvingperformance characteristics against forces in a downwardly projectingdirection.

FIGS. 24-28 illustrate various web patterns. FIG. 24 shows ansubstantially diamond-shaped web pattern; FIG. 25 shows a circular webpattern; FIG. 26 shows a combination of diamonds and vertical bars as aweb pattern; FIG. 27 shows a triangular web pattern (with trianglesbeing equilateral and effectively forming hexagons as well); and FIG. 28shows a rectangular web pattern.

The reinforcing web patterns may extend generally the full height of thesidewall and terminate at or near the top and bottom of the sidewall.Other embodiments include patterns completely covering the sidewall,patterns formed in the center of a sidewall surrounded by flat (non-web)portions of sidewall, patterns formed in sections spaced vertically fromeach other in a single sidewall, and patterns that extend only a part ofthe height of the side wall, or may be any of a wide variety of otherconfigurations and combinations. For round containers, the pattern maybe generally uniform about the circumference. The location of thesidewall reinforcing web patterns can be helpful in improvingperformance characteristics against forces in a downwardly projectingdirection. Also, pattern and shapes discussed in the previous paragraphscan be selected to provide varying degrees of strength for a givenspecific location of the pattern. Additionally, the reinforcing webpatterns may be provided on inside surfaces of the sidewall, on outsidesurfaces of the sidewalls, or anywhere between those extremes (some ofthe web showing on both inside and outside of the sidewalls). FIGS.29-32 illustrate elevation views of web patterns formed in the center ofa sidewall surrounded by flat (non-web) portions of sidewall.

The reinforcing web patterns have a thickness greater than the thicknessof the surrounding sidewall. For example, a container having wallthickness of 0.050″ in non-webbed areas may have a web thickness of0.075.″ As such, the portion comprising the reinforcing web adds anextra 0.025″ to the adjacent or underlying 0.050″ wall. In this example,the reinforcing web adds a thickness amount less than the adjacent orunderlying wall thickness. This depth of the reinforcing web pattern maybe selected in order to provide varying degrees of strength for a givenwall thickness and/or specific location on the sidewall.

Thus, designers may customize the reinforcing web by modifying thechannel shape and size, the pattern, the location and the thickness,thereby adding strength to virtually any desired location and to only inthe areas in which it is most needed.

The corners of the container may include an integral reinforcing web ofincreased wall thickness as compared to adjacent non-web portions forproviding structural support to the corners. Incorporating reinforcingweb patterns within a corner provides many of the same benefits as itdoes with non-cornered portions of the sidewall. The reinforcing web onthe corners may be substantially a continuation of the pattern presenton the other portions of the sidewall. The pattern may be generallybalanced along the vertical centerline of the corner, or the pattern maybe centered along the vertical centerline of the corner.

The wall thickness of the corners may be thicker than the rest of thesidewall. For embodiments having square, rectangular or other corneredcontainers, the wall thickness of the corners normally needs to bethicker than the rest of the sidewall because most of the compressiveload (in stacked pallets of filled containers) is supported on thecorners. Providing stronger corners can improve the performance of thecontainer and/or allow a given container to exceed the performancelimitations faced by conventional constructions.

The curvature of the corners may be kept substantially constantthroughout the height of the container, rather than reducing to atighter radius near the bottom. Containers with non-tapered corners havea greater space or gap between containers when nested with each other,thereby ensuring easier release of the containers when they arede-nested. Since the containers can de-nest from each other faster,filling line speed can increase (because the containers can be deliveredto the filling lines at a faster rate) and overall efficiency of use canbe improved.

In this respect, FIGS. 33-36 provide an illustrated comparison betweennested containers having corners of a substantially constant radius andnested containers having tapered corners, respectively. FIG. 33 shows across-section of the corners of two nested containers of the invention(Container X nested inside Container Y), both having a generallyconstant (non-tapering) radius of curvature in their respective cornersections. FIG. 34 shows a cross-section of the corners of two nestedcontainers (Container W nested inside Container Z), both having agenerally tapered radius of curvature (a radius that is smaller near thebottom of the container as compared to the top). Comparing FIGS. 33 and34, nested containers having tapered corners have less space or gapbetween the containers at the corners, thereby creating undesiredfrictional engagement.

FIGS. 35A and 35B are similar to FIG. 34 but show a more completeelevational cross-section of two nested containers having a generallytapered radius of curvature, with 35B taken along the line 35B-35B.FIGS. 36A and 36B are similar to FIGS. 35A and 35B, but show two nestedcontainers having a tapered corner radius. Comparing FIGS. 35 and 36,nested containers having a substantially constant radius have a cornergap of 0.0494″ while nested containers having tapered corners have acorner gap of 0.0291.″ Again, nested containers having tapered cornershave less space or gap between the containers at the corners, therebycreating undesired frictional engagement.

In addition to avoiding undesired frictional engagement, greater spaceor gap between containers facilitates the incorporation of increasedtotal corner wall thickness and/or thicker web areas formed at thecorner are, thereby providing for a stronger corner. In this respect,FIGS. 37-38 provide an illustrated comparison between nested containershaving corners of a substantially constant radius and nested containershaving tapered corners.

FIGS. 37A and 37B are similar to FIGS. 35A and 35B, but show two nestedcontainers having a generally non-tapered (constant) corner radius and adiamond pattern web formed on the sidewall and corner. FIGS. 38A and 38Bare similar to FIGS. 36A and 36B, but show two nested containers havinga tapered corner radius and a diamond pattern web formed on the sidewalland corner. Comparing FIGS. 37 and 38, both sets of nested containershave substantially equal corner gaps. However, the nested containershaving a substantially constant radius have a corner wall thickness of0.040″ and corner wall diamond web pattern thickness of 0.055″ while thenested containers having tapered corners have a corner wall thickness of0.020″ and corner wall diamond pattern thickness of 0.035.″ Thus,containers where the curvature of the corners is kept substantiallyconstant throughout the height of the container allows for increasecorner total corner wall thickness and/or thicker web areas at thecorner without decreasing nestability.

In another aspect affecting nestability, containers may include one ormore vertical ribs for keeping containers spaced from each other whennested. The vertical ribs may be located at the corners near the bottom.The vertical ribs may also span the substantially entire length of thesidewalls. Vertical ribs may be integrally formed with the sidewalls.Also, the vertical ribs may be integrally formed with the sidewalls andthe reinforcing web.

Sidewalls of containers may be designed to be bowed outwardly, that isaway from the container interior. The bowed sidewall may have anoutwardly arced or curved shape in horizontal cross-section or mayinclude a wide variety of cross-sectional shapes besides smooth concaveout arcs or curves or straight lines. Bowing the sidewalls outwardlyhelps ensure that compressive loads imposed upon the container force thesidewall outward and thereby take advantage of the hoop strength of thesidewall. In contrast, containers with straight sidewalls (i.e. thecenter is the same width as the corner) tend to buckle under load orincur other structural failures and the sidewalls collapse in or out.Containers including bowed sidewalls better resist collapse fromstacking forces (compression loads imposed substantially verticallydownwardly due to stacking of other filled containers or otherwise).Additional strengthening of the containers is provided by forming thebowed sidewalls in combination with the web patterns. Bowed portions maybe located between corners.

Sidewalls may be tapered so that the top opening formed by the upperedge is larger than the base of the container. In other words, the widthof the container from one sidewall to its opposite sidewall at the topis wider than the width at the bottom. Tapered sidewalls enable nestingof one container with another. Nesting facilitates manufacturing,handling, and storage of containers in an unfilled state. It isimportant to provide containers with good nestability so that the volumethey require prior to filling/usage is reduced. Additionally, taperingcan be such that an arced or curved sidewall shape (i.e. outwardly bowedsidewalls) is generally continuous in cross-section for substantiallythe entire height of the sidewalls. In this case, the radius of the arcsor curves at the bottom of the container sidewalls would be smaller thanthe radius of the arcs or curves at the top of the container sidewalls.Thus, tapering of the sidewalls can impact the ability of any givencorner design to maintain desired strength (i.e. increased cornerthickness) and to maintain sufficient spacing between nested containers.

The container may include one or more horizontal ribs. The horizontalribs may extend substantially about the sidewalls or may surround theperiphery of the container's exterior. The horizontal ribs may beaffixed or integrated to the sidewalls near the top of the container orany desired location. The horizontal ribs may be any desired pattern,including being interrupted or having a non-uniform width. The angle,frequency, thickness and other characteristics of the horizontal ribsmay be customized depending on a variety of factors. Just as bowing thesidewalls outwardly helps ensure that compressive loads imposed upon thecontainer sidewall force the sidewall outward and thereby take advantageof the hoop strength of the sidewall, the effect of the horizontal ribsis to provide additional hoop strength to the sidewall. Thereby, thehorizontal ribs improve stackability and structural integrity againstinternal loads and vertical compressive forces.

The containers may include one or more handles and/or attachment points.They may be formed on the sidewalls and may be connected to orintegrally formed with the one or more horizontal ribs. The entireintersection of horizontal ribs, vertical ribs, flow leaders, andsidewall portions can be integrally formed or otherwise bonded.

The base may include a gate site and flow leaders on the base. The flowleaders may connect to and extend outwardly from the gate site to thesidewalls. The flow leaders may connect to the reinforcing web. The flowleaders have increased thickness relative to the wall thickness of thebase. In other embodiments, the base may include one or more flowleaders and one or more gate sites, including on the sidewall itself.The flow leaders may be oriented and dimensioned at any suitable angleand size, and may be spaced a selected distance apart from each other,depending on the materials used, the applications for which thecontainer is intended and other factors. Multiple series of flow leadersmay be introduced within a single container to provide variations ininjection flow. The path of the flow leaders may overlap each other insome embodiments. FIG. 39 illustrates an embodiment where flow leadersare each directed respectively from a gate site on the container bottomtoward each of four sides.

For embodiments having round or square containers, flow leaders may begenerally uniform about the circumference. For rectangular containers,however, proportionally fewer flow leaders may lead to the short sidescompared to the long sides, because there is less area on the shortsides and therefore less material is needed to form those areas. If toomuch plastic is delivered to the short sides, the plastic fills theshort sides faster than the long sides, and excess plastic flows fromthe top of the short side over to the top of the long side and joinswith the plastic flowing up the long side along the sidewall, whichweakens the container. Flows from the sidewalls should reach the toproughly simultaneously during the molding process. Thus, a rectangularcontainer with a long side of 10.5 and a short side of 8.5 may use asimilar ratio of flow leaders (and/or total volume capacity) as betweenthe long and short sides.

When a container is fabricated in a molding process, molten material(for example, plastic) is introduced into a mold at a sprue injectionsite, which may be a gate injection site at the center of the bottom ofthe container. The plastic then flows up the sidewalls to the top of thecontainer until the mold is completely full.

Flow leaders facilitate the flow of molten material from the gate siteto the channels of the reinforcing web, so that the material is injectedmore efficiently into the thicker webbing areas in greater volume thanto the thinner non-web areas. Flow leaders enable the reinforcing web tofill with less pressure relative to using a generally uniform basethickness within the mold (which would not focus the injected materialinto the thicker web channels before spreading out into the thinnerportions of the container sidewalls. Lower injection pressure (to injectplastic into a mold) means less energy need to manufacture that product.

Lower injection pressure additionally enables the use of other materialsthan those in prior art design. Because of the improved injectionperformance provided by the flow leaders and/or web pattern, containerscan be made from less expensive and/or more easily recycled materials.Because of improved injection performance, container can be made frompolypropylene, which typically has better top load-bearing performancecharacteristic, rather than polyethylene. Polypropylene may be preferredover polyethylene in order to withstand anticipated vertical compressionloads or other forces. Yet, containers may be formed of any suitablystrong, lightweight material, for example plastics, includingpolyethylene and polypropylene.

Furthermore, flow leaders help strengthen the base portion of thecontainer, and thereby strengthen the entire container generally.Accordingly, the base portion obtains performance characteristics thatcould only be achieved by using more total material and having moretotal weight. Thus, less raw materials are needed for each container andtransportation costs are reduced because the container weighs less.

In some embodiments, the flow leaders of the base may have a taperedshape, for example, gradually tapering to a maximum thickness near thecenter of the channel's cross-section, and/or having curved exteriorsurfaces. That is, the flow leaders may have curved surfaces from across-sectional perspective. Tapered channels may improve theperformance of the container. For example, emptying or dispensing thecontainer's contents during use becomes easier and/or more complete,reduced flexibility due to sharp edges that harden the container inthose sharp areas is avoided by spreading stresses/loads throughoutchannel, and the container is release faster from a nested state.Furthermore, when employed in the, context of a molding process, themolding process may be improved. For example, the molded container iseasier to remove from the mold, the amount of material required to forma suitable container is decreased and the molten material more easilydispenses through the mold.

The flow leaders 18 may have a thickness greater than a thickness of thesurrounding sidewall. The flow leaders 18 may have an additionalthickness less than the adjacent or underlying base wall thickness.

Flow leaders may form a web pattern of their own or the container basemay have a combination of flow leaders and web patterns. The webpatterns may include channel shapes in a pattern of a series of rows andcolumns of relatively increased wall thickness. The pattern may be anythat provide the benefits, including circles, ovals, arches, rectangles,hexagons, honeycombs, triangles, diamonds, combination of diamonds andvertical bars. The pattern may include sharp or smooth patterns orelements, a mix of various patterns, mixed sizes of the size ordifferent shapes, spaces irregularities within an otherwise regularpattern, or may even be somewhat random.

Containers may also include lids configured to fit the containers. Theengaging lip 40 is preferably configured to matingly engage with acorresponding lid. The lid may itself incorporate web patterns.Additionally, other portions of other products may include somecombination of flow leaders and/or web patterns.

The following description relates methods of manufacturing containersaccording to embodiments of the present invention.

Methods of manufacturing containers includes molding and bonding andother fabrication techniques. In the case of bonding, the containerelements are bonded together, for example by welding or gluing, althoughnot all of the container elements have to be bonded together.

In the case of molding, the entire container may be integrally formed.Exterior portions of molds form the outer shape for each container, andinterior molds portions of molds form the inner shape for eachcontainer. Shapes, such as the reinforcing web patterns, may be formedby providing corresponding shapes within the molds and introducingmolten material into the mold at a sprue site or gate site. Finally, themolded part is removed from the mold.

Methods include injection molding of plastic and other materials,including polyethylene and polypropylene. For injection molding methods,plastic or another material is injected into the mold at one or moresprue injection sites or gate injection sites. The plastic, for example,flows from the injection site to the base of the container. The plasticthen flows up the sidewalls to the top of the container, until the moldis completely filled. Flows from the sidewalls should reach the top ofthe container roughly simultaneously. Otherwise, excess plastic willflow from over the top and join with plastic flowing up along thesidewall, which may weaken the container.

For injection molding of containers that include flow leaders andreinforcing webs, the plastic or other material flows from the injectionsite to the base of the container. The flow leaders then facilitate flowof the molten plastic or other material from the injection site to thelowermost portions of the sidewall reinforcing web and then through therelatively wide channels of the reinforcing web. Because material isinjected more efficiently into the thicker webbing areas in greatervolume than the thinner non-web areas, material is injected into thethicker web channels before spreading out into the thinner portions ofthe underlying sidewall. Thereby, the reinforcing web fills more easilyand with less pressure than by using a substantially uniform bottomthickness within the mold.

Accordingly, plastic is more easily dispensed through the mold,injection performance is improved, and the injection pressure or forcerequired to inject is reduced. Thus, containers can be made lessexpensively and/or from more easily recycled materials.

The following description relates to methods of designing containersaccording to embodiments of the present invention.

A CAD method can be used for complicated geometries of the container orother object. When combining integral reinforcing web portions of asidewall with arched sidewalls, it is difficult to automatically createand manipulate within CAD computer software. CAD computer softwareprograms can create straight (non-bowed) sidewalls having reinforcementwebbing and also can create bowed sidewalls without reinforcementwebbing (e.g., sidewalls having a uniform thickness). However, nocomputer software of which the inventors are aware is able toautomatically create and manipulate designs having both those features.

To facilitate the design and manufacture of such more complex containersand other parts using computer technology, one of several hybridprocesses or methods can be used. For example, a conventional CADsoftware system can be used to create a straight-walled container havinga desired web pattern formed therein. A user can then manipulate thatdesign by hand, within the CAD program, to pull the sidewall into adifferent, non-dashed straight alignment such as a bow. Each of thevarious elements of the strengthening pattern in the sidewall must berepositioned by hand into the new “plane” of the sidewall (or other partof the product being fabricated), but once the task is accomplished andsaved, the electronic design can be used for purposes of mold creationor other manufacturing steps and processes, just as with any otherelectronic design.

Additionally, during design, many factors can be considered and adjustedto provide a desired balance of strength, weight, and performance forany specific method of fabrication and final design of the container orother item. These include, by way of example and not by way oflimitation, the anticipated loads, the materials from which the thing isto be fabricated, the dimensions of the flow leaders and reinforcingelements within the sidewall, the thickness of the sidewall at locationsother than those reinforcing elements, the “sharpness” of any change indimensions of the flow leaders and/or the sidewall reinforcing patternelements, the sharpness of any change in direction of the flow leadersand/or reinforcing elements, the frequency and regularity of the patternof the flow leaders and/or reinforcing elements, the spacing between theflow leaders and/or reinforcing elements, and other factors and designparameters.

The following description relates an example illustrating advantages ofembodiments of the present invention.

The example compares three similarly-sized and -shaped 4-gallon capacityrectangular containers. One (Container A) was a polyethylene materialcurrently marketed by the assignee of the present invention. The othertwo were polypropylene, one of which (Container B) had conventionaluniform thickness sidewalls but included flow leaders formed in itsbottom to facilitate the flow of plastic from the sprue injection siteto the sidewalls. The other (Container C) included both (1) the sameflow leaders as Container B and (2) a reinforcing web pattern in thesidewall.

For these embodiments, the same exterior mold was used in each case(resulting in an identical outer shape for each of Containers A, B, andC), and the interior portion of the injection-molding mold was changedto achieve the differences discussed above. Similar results (asdiscussed herein) should be achieved in other embodiments (such as wherethe flow leaders/web patterns are formed on the exterior of thecontainer, or on both the interior and exterior). The size and capacityand other characteristics of the compared containers were not critical.

The table below shows some of the relevant comparative measurements forthe three containers (all measurements are approximate):

Container (all Wall Metric Tonnage Weight of were 4 gallons ThicknessCompression of Pressure molded capacity) Material (in.) Strength (lbs.)Required to Inject container (gms) A (prior art) polyethylene 0.080 1260500 700 B (only flow polyethylene 0.035 1060 700 425 leaders - no webpattern in sidewall) C (both flow polypropylene 0.050 at 1330 450 470leaders AND webbed areas, web pattern in 0.035 at non- sidewall) webbedareas

As indicated in the table above, a container without a web and flowleader pattern (Container A) used approximately 50% more plastic (700gms compared to 470 gms). It required a higher tonnage to inject, andactually had a lower compression strength (it was not as strong undercompression/vertical loading—1260 lbs. compared to 1330 lbs.).Accordingly, less material was injected yet with better productperformance.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the invention. Thus, it isintended that the present invention cover the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

1. A container, comprising: a substantially solid base and at leastthree sidewalls integrally formed with and extending upwardly from thebase and having corners portions therebetween, an internal cavity formedby the sidewalls and the corner portions, the internal cavity havingwith an opening opposite the base; wherein the sidewalls and cornerportions include a continuous integral reinforcing web extending fromthe sidewalls and corner portions into the internal cavity; wherein thecorner portions have a curved cross-section of predetermined radius ofcurvature wherein the predetermined radius of curvature is substantiallyconstant through the height of the corner portions; and wherein theintegral reinforcing web has a repeating geometric pattern having apattern frequency, wherein the pattern frequency is the substantiallythe same in the corner portions and the sidewalls.
 2. The container ofclaim 1, wherein the sidewalls taper outward from the base to theopening.
 3. The container of claim 1, further comprising flow leaders inthe base extending from a gate site in the base to the reinforcing web.4. The container of claim 1, the sidewall having a predeterminedthickness and the reinforcing web having a thickness greater than thesidewall.
 5. The container of claim 4, wherein the reinforcing web has aplurality of channels, the channels having a cross section in which amid-point has a greater thickness than an edge point of the channel. 6.The container of claim 1 wherein the repeating geometric pattern is adiamond pattern formed of a plurality of crossing channels, the channelsextending from the sidewall a predetermined depth into the internalcavity.
 7. The container of claim 6, wherein the channels have curvedsurfaces from a cross-sectional perspective.
 8. The container of claim6, wherein the channels have a substantially constant width.
 9. Thecontainer of claim 7, wherein the channels have a depth as measured fromthe sidewall that is thicker at a mid-point of the width of the channelsthan at an edge portion of the channel.
 10. The container of claim 1,wherein the reinforcing web extends along substantially full height ofthe sidewalls.
 11. The container of claim 1, wherein the reinforcing webin the corner portion is substantially balanced along a verticalcenterline of each corner.
 12. The container of claim 1, wherein thewall thickness of the corner portions is greater than the wall thicknessof the sidewalls.
 13. The container of claim 1, wherein the cornerportions have a single concave corner shape, a double concave cornershape or an angled corner shape.
 14. The container of claim 1, furthercomprising one or more integral vertical separating ribs.
 15. Thecontainer of claim 1, further comprising at least one externalhorizontal reinforcing rib extending from the sidewall.
 17. Thecontainer of claim 1, wherein the container is made of injection-moldedplastic.
 18. The container of claim 1 in combination with a lid.
 19. Thecontainer of claim 18, wherein the container is made of injection-moldedplastic.